<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <title>图形封装</title>
    <style>
        body {
            margin: 0;
            overflow: hidden;
        }

        #canvas {
            background-color: antiquewhite;
        }
    </style>
</head>

<body>
<canvas id="canvas"></canvas>
<!-- 顶点着色器 -->
<script id="vertexShader" type="x-shader/x-vertex">
      attribute vec4 a_Position;
      void main(){
          gl_Position=a_Position;
          gl_PointSize=20.0;
      }
    </script>
<!-- 片元着色器 -->
<script id="fragmentShader" type="x-shader/x-fragment">
      void main(){
          gl_FragColor=vec4(1,1,0,1);
      }
    </script>
<script type="module">
  import { initShaders } from "../jsm/Utils.js";
  import Poly from '../jsm/Poly.js'

  const canvas = document.querySelector("#canvas");
  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;

  // 获取着色器文本
  const vsSource = document.querySelector("#vertexShader").innerText;
  const fsSource = document.querySelector("#fragmentShader").innerText;

  //三维画笔
  const gl = canvas.getContext("webgl");

  //初始化着色器
  initShaders(gl, vsSource, fsSource);


  //声明颜色 rgba
  gl.clearColor(0, 0, 0, 1);
  //刷底色
  gl.clear(gl.COLOR_BUFFER_BIT);

  const poly = new Poly({
    gl,
    vertices: [0, 0.2]
  })
  poly.draw()

  setTimeout(() => {
    poly.addVertice(-0.2, -0.1)
    gl.clear(gl.COLOR_BUFFER_BIT);
    poly.draw()
  }, 1000);

  setTimeout(() => {
    gl.clear(gl.COLOR_BUFFER_BIT);
    poly.draw(['POINTS', 'LINE_STRIP'])
  }, 2000);

</script>
</body>

</html>
